staging:wlan-ng: use memdup_user instead of kmalloc/copy_from_user

memdup_user() is shorter and safer equivalent
of kmalloc/copy_from_user pair.

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
Link: https://lore.kernel.org/r/20210213120527.451531-1-insafonov@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/wlan-ng/p80211netdev.c b/drivers/staging/wlan-ng/p80211netdev.c
index a15abb2..6f9666d 100644 (file)
--- a/drivers/staging/wlan-ng/p80211netdev.c
+++ b/drivers/staging/wlan-ng/p80211netdev.c
@@ -569,24 +569,22 @@ static int p80211knetdev_do_ioctl(struct net_device *dev,
                goto bail;
        }
 
-       /* Allocate a buf of size req->len */
-       msgbuf = kmalloc(req->len, GFP_KERNEL);
-       if (msgbuf) {
-               if (copy_from_user(msgbuf, (void __user *)req->data, req->len))
-                       result = -EFAULT;
-               else
-                       result = p80211req_dorequest(wlandev, msgbuf);
+       msgbuf = memdup_user(req->data, req->len);
+       if (IS_ERR(msgbuf)) {
+               result = PTR_ERR(msgbuf);
+               goto bail;
+       }
 
-               if (result == 0) {
-                       if (copy_to_user
-                           ((void __user *)req->data, msgbuf, req->len)) {
-                               result = -EFAULT;
-                       }
+       result = p80211req_dorequest(wlandev, msgbuf);
+
+       if (result == 0) {
+               if (copy_to_user
+                   ((void __user *)req->data, msgbuf, req->len)) {
+                       result = -EFAULT;
                }
-               kfree(msgbuf);
-       } else {
-               result = -ENOMEM;
        }
+       kfree(msgbuf);
+
 bail:
        /* If allocate,copyfrom or copyto fails, return errno */
        return result;